This present disclosure relates to a light emitter device (LED) driving device. Specifically, embodiments relate to an LED driving device, which receives a rectified AC input supplied to an LED string.
An LED string includes a plurality of LED elements, and may be directly connected to an AC line. A sinusoidal wave rectified from an AC input is supplied to the AC line, and the sinusoidal wave may control the number of LED elements to be turned on in the LED string.
In such an LED driving device described above, Inverse Compton (IC) scattering may occur due to resistance differences among a plurality of resistors connected to pins that control a degree of illumination of a plurality of LED elements, input offsets of amplifiers in the LED driving device, and so on. A trimming process is required to reduce the IC scattering of the LED driving device, and the trimming process may increase production costs.
In addition, when a waveform of a current flowing through the LED string has a step-like profile, a power factor (PF) and total harmonic distortion (THD) may be deteriorated.